Abstract
Nd3+-doped glasses in the composition (50-x) B2O3-10 PbO-10 BaO-10 Al2O3-10 ZnO-10 Na2O-(x) Nd2O3 (x = 0.0, 0.1, 0.25, 0.5, 0.75, 1.0, 1.5, and 2.0 mol %) were fabricated using melt quenching method. Upon 592 nm visible and 808 nm LD excitations, the luminescence spectra show a strong F-4(3/2) -> I-4(11/2) (1.06 m) emission transition, and two less intense F-4(3/2) -> I-4(9/2) (0.89 mu m) and F-4(3/2) -> I-4(13/2) (1.331 mu m) emission transitions. The intensity of such emissions increases up to 0.5 mol % Nd3+, and above this doping level, quenching occurs. For 0.5 mol % Nd3+-doped glass, following Judd-Ofelt intensity parameters and emission spectrum, A(R), tau(R), beta(R) and beta(exp), including Delta lambda(eff) sigma(em)(lambda(p)), (sigma(em) x (Delta lambda(eff))) and (sigma(em) x (tau(rad))), are derived for Nd3+ ion F-4(3/2) -> I-4(11/2) and F-4(3/2) -> I-4(13/2) fluorescence transitions. The highest sigma(em)(lambda(p)) for the 1.06 and 1.331 mu m fluorescence bands are found to be 6.216 x 10(-20) and 2.295 x 10(-20) cm(2), respectively. The F-4(3/2) level lifetimes are found to decrease with an increase in Nd2O3 content and the decay curves of the glass up to 1.5 mol % Nd3+ exhibit single exponential nature. From 'tau(exp)' of the Nd3+: F-4(3/2) level, quantum efficiency (eta), ((sigma(em) x (tau(exp))), and saturation intensity (I-S) are 48.87%, 51.09 x 10(-25) cm(2)s and 3.67 x 10(8) W/m(2), respectively, for the 0.5 mol % Nd3+-doped glass. Higher thermal stability, very low chi, high A(R), large beta(exp)., moderate tau(R), large gain bandwidth and high optical gain values indicate that 0.5 mol % Nd3+-doped glass could be a potential gain medium for solid-state NIR lasers at 1.06 mu m. Moreover, for the 1.331 pm emission, large Delta lambda(eff) and the theoretical gain coefficient value of 1.579 dB/cm, evaluated with an excited Nd3+ ion fractional factor of 0.6, indicate that this glass might be a promising candidate in developing O-band optical fiber amplifiers. (C) 2018 Elsevier B.V. All rights reserved.